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The anterior cruciate ligament (ACL) originates from the mesenchyme and becomes a distinct cruciate ligament from the posterior cruciate ligament (PCL) by week 10. The ACL is associated with two distinct bundles, anteromedial (AM) and posterolateral (PL), that originate on the lateral femoral condyle and insert on the intercondylar spine of the tibia. As the primary stabilizer of the knee, the ACL is responsible for resisting anterior translation and rotation of the tibia on the femur. Both the physis (growth plate) and tibial tuberosity lie in close proximity to the ACL. Pediatric ACL reconstruction can be challenging due to the risk of causing damage to the physis, articular cartilage, lateral collateral ligament (LCL), popliteus tendon, and meniscus. Future prospective studies are needed to determine optimal techniques for management of ACL injuries in those with open growth plates.

Background: Revision anterior cruciate ligament (ACL) reconstruction has been documented to have worse outcomes compared with primary ACL reconstruction. Hypothesis: Certain factors under the control of the surgeon at the time of revision surgery can both negatively and positively affect outcomes. Study Design: Case-control study; Level of evidence, 3. Methods: Patients undergoing revision ACL reconstruction were identified and prospectively enrolled between 2006 and 2011. Data collected included baseline demographics, intraoperative surgical technique and joint disorders, and a series of validated patient-reported outcome instruments (International Knee Documentation Committee [IKDC] subjective form, Knee Injury and Osteoarthritis Outcome Score [KOOS], Western Ontario and McMaster Universities Osteoarthritis Index [WOMAC], and Marx activity rating scale) completed before surgery. Patients were followed up for 2 years and asked to complete an identical set of outcome instruments. Regression analysis was used to control for age, sex, body mass index (BMI), activity level, baseline outcome scores, revision number, time since last ACL reconstruction, and a variety of previous and current surgical variables to assess the surgical risk factors for clinical outcomes 2 years after revision ACL reconstruction. Results: A total of 1205 patients (697 male [58%]) met the inclusion criteria and were successfully enrolled. The median age was 26 years, and the median time since their last ACL reconstruction was 3.4 years. Two-year follow-up was obtained on 82% (989/1205). Both previous and current surgical factors were found to be significant contributors toward poorer clinical outcomes at 2 years. Having undergone previous arthrotomy (nonarthroscopic open approach) for ACL reconstruction compared with the 1-incision technique resulted in significantly poorer outcomes for the 2-year IKDC ( P = .037; odds ratio [OR], 2.43; 95% CI, 1.05-5.88) and KOOS pain, sports/recreation, and quality of life (QOL) subscales ( P ≤ .05; OR range, 2.38-4.35; 95% CI, 1.03-10.00). The use of a metal interference screw for current femoral fixation resulted in significantly better outcomes for the 2-year KOOS symptoms, pain, and QOL subscales ( P ≤ .05; OR range, 1.70-1.96; 95% CI, 1.00-3.33) as well as WOMAC stiffness subscale ( P = .041; OR, 1.75; 95% CI, 1.02-3.03). Not performing notchplasty at revision significantly improved 2-year outcomes for the IKDC ( P = .013; OR, 1.47; 95% CI, 1.08-1.99), KOOS activities of daily living (ADL) and QOL subscales ( P ≤ .04; OR range, 1.40-1.41; 95% CI, 1.03-1.93), and WOMAC stiffness and ADL subscales ( P ≤ .04; OR range, 1.41-1.49; 95% CI, 1.03-2.05). Factors before revision ACL reconstruction that increased the risk of poorer clinical outcomes at 2 years included lower baseline outcome scores, a lower Marx activity score at the time of revision, a higher BMI, female sex, and a shorter time since the patient’s last ACL reconstruction. Prior femoral fixation, prior femoral tunnel aperture position, and knee flexion angle at the time of revision graft fixation were not found to affect 2-year outcomes in this revision cohort. Conclusion: There are certain surgical variables that the physician can control at the time of revision ACL reconstruction that can modify clinical outcomes at 2 years. Whenever possible, opting for an anteromedial portal or transtibial surgical exposure, choosing a metal interference screw for femoral fixation, and not performing notchplasty are associated with significantly better 2-year clinical outcomes.

Objectives: To study trochlear morphology during maturation in children using MR imaging. Methods: The study population consisted of 22 knees (11 M/11 F) from pediatric cadavers, aged 1 month to 10 years (provided by Allosource, Inc.) An IRB waiver approval applied. MR Sequence: 3D-GRE sequence for Susceptibility-Weighted Magnetic Resonance Imaging: a non-invasive technique allowing precise distinction between cartilage vs. osseous morphology. For each sample, the MRI biometric analysis was conducted on the axial/sagittal/coronal views analyzing three slices; the most proximal slice corresponding to the location of full cartilage trochlear groove coverage. Patellar measurements were not performed due its absence in many specimens. Biometric analysis included lateral/media/central trochlear height, cartilaginous sulcus angle (CSA), osseous sulcus angle (OSA), trochlear depth (TD), and trochlear facet length asymmetry. Sex comparisons were considered when one or more specimens from both sexes of the same age were available; 12 knees total spanning 4 age groups (ages 1, 3, 4 and 7 years). Results: Four samples were excluded due to low quality images. Morphology: Both lateral and medial condylar height increased by 12% from distal slices to proximal slices; lateral trochlear height > medial trochlear height at all ages. There was a discrepancy between lateral and medial trochlear facet length which was more evident in older samples (lateral > medial). The thickest cartilage was present on the lateral condylar facet in the younger specimens. Comparative trends between male/females: Female samples had a shallower cartilaginous sulcus (CSA) and osseous sulcus (OSA) than males. Development of osseous and cartilaginous trochlear contour: A cartilaginous sulcus is present in the 3mo. old specimen and continues to deepen up to the age of 4 years. The shape of the osseous center evolves from round (1 month), to oval (9 month), to square (2 years), with no distinct bony trochlear sulcus, although a well formed cartilaginous sulcus already is in place. At 5 years the shape of the osseous center resembles aviator glasses, with the first evidence of a sulcus forming. The bony contour of the adult distal femur resembles the cartilaginous contour at 7-8 years. Discussion: From the earliest stage of the development, the female trochlea is flatter with less groove depth than that of males. The development of the shape of the OSA does not follow that of the CSA, suggesting that other forces (possibly from the patella) dictate the contour of the mature bony trochlear groove. Conclusion: Our sample suggests: 1) a developmental tendency for females to have shallower (i.e., more dysplastic) grooves; 2) the lateral trochlea is higher (trochlear height) and wider (trochlear facet length) during growth than the medial in both sexes; and 3) The development of the osseous sulcus shape lags behind the development of the cartilagenous sulcus shape in our sample population. The anatomic findings are consistent with clinical studies on trochlear dysplasia in females, and suggests that trochlear development differences may play a critical role in patella instability. [Figure: see text]

Objectives: Over the last 50 years, the genesis of OCD lesions has been thought secondary to a primary bone necrosis origin. This theory has been challenged recently, as histological studies performed on specimens obtained from asymptomatic mammals, have revealed that ischemic necrosis of epiphyseal cartilage (rather than bone) is the precursor lesion of osteochondrosis dissecans (OCD) in several animal species. The earliest lesion identified histologically is osteochondrosis (OC) latens, in which the area of necrosis is confined to epiphyseal cartilage. As the ossification front advances, the area of necrosis causes a delay/failure in endochondral ossification that is visible radiographically and by CT and is termed OC manifesta. Juvenile osteochondritis dissecans (JOCD) in children has many similarities to OCD in animals; however, subclinical disease in children has not been studied due to the invasive nature of this work and the difficulty in obtaining appropriate cadaveric specimens. Lesions of OC latens are not recognized in children, and lesions resembling OC manifesta identified by CT are often considered to be normal ossification variants. Previous work by our group identified 32 suspected OC manifesta lesions in the medial and lateral femoral condyles (MFC and LFC) and the lateral trochlear ridge (LTR) in 14 cadaveric specimens from children ranging in age from 7 to 11 years. Our aim was to determine if skeletally immature human knees contained histological evidence of delayed endochondral ossification occurring secondary to ischemic necrosis of epiphyseal cartilage. Methods: Eleven sites (4 MFC, 4LFC, 3LTR) containing suspect OC manifesta lesions identified on CT from five male children (age range 7-11 years) were decalcified in 10% EDTA. Areas corresponding to the CT lesions were trimmed into 3-mm thick slabs (n=2-4 slabs/site), processed into paraffin, sectioned at 5 µm, and stained with hematoxylin and eosin. All sections (n= 30 total) were examined by four veterinary pathologists/radiologists with extensive experience in the study of OC in pigs and horses. Results: All sites examined contained at least one section containing histological evidence of one or more areas of OC manifesta Lesions were evidenced by focal failure of endochondral ossification accompanied by remnants of necrotic blood vessels, chondrocyte necrosis with matrix degeneration. Some lesions were accompanied by evidence of repair/healing response, including chondrocyte clusters, proliferating blood vessels, and fibrous connective tissue. Conclusion: Similar to other mammals, human OCD lesions appear to develop as a primary defect secondary to avascular necrosis of epiphyseal cartilage, rather than primary avascular necrosis in bone. Our findings strongly support a common pathogenesis of OCD in humans and mammals. Historically, ossification variants have been considered a developmental anomaly with a benign clinical course. Our histologic findings suggest that ‘ossification variants’ may in face be delayed presentations of a continuum of OCD lesion development that starts years earlier due to primary epiphyseal cartilage necrosis. Some of these ‘variants’ may progress to healing, but many may progress to frank ‘osteochondritis dissecans’, suggesting that these lesions that are idenfitifed on xray or with MRI sequences require close follow-up.

Background: While revision anterior cruciate ligament reconstruction (ACLR) can be performed to restore knee stability and improve patient activity levels, outcomes after this surgery are reported to be inferior to those after primary ACLR. Further reoperations after revision ACLR can have an even more profound effect on patient satisfaction and outcomes. However, there is a current lack of information regarding the rate and risk factors for subsequent surgery after revision ACLR. Purpose: To report the rate of reoperations, procedures performed, and risk factors for a reoperation 2 years after revision ACLR. Study Design: Case-control study; Level of evidence, 3. Methods: A total of 1205 patients who underwent revision ACLR were enrolled in the Multicenter ACL Revision Study (MARS) between 2006 and 2011, composing the prospective cohort. Two-year questionnaire follow-up was obtained for 989 patients (82%), while telephone follow-up was obtained for 1112 patients (92%). If a patient reported having undergone subsequent surgery, operative reports detailing the subsequent procedure(s) were obtained and categorized. Multivariate regression analysis was performed to determine independent risk factors for a reoperation. Results: Of the 1112 patients included in the analysis, 122 patients (11%) underwent a total of 172 subsequent procedures on the ipsilateral knee at 2-year follow-up. Of the reoperations, 27% were meniscal procedures (69% meniscectomy, 26% repair), 19% were subsequent revision ACLR, 17% were cartilage procedures (61% chondroplasty, 17% microfracture, 13% mosaicplasty), 11% were hardware removal, and 9% were procedures for arthrofibrosis. Multivariate analysis revealed that patients aged Conclusion: There was a significant reoperation rate after revision ACLR at 2 years (11%), with meniscal procedures most commonly involved. Independent risk factors for subsequent surgery on the ipsilateral knee included age

Background: The reliability of assessing healing on plain radiographs has not been well-established for knee osteochondritis dissecans (OCD). Purpose: To determine the inter- and intrarater reliability of specific radiographic criteria in judging healing of femoral condyle OCD. Study Design: Cohort study (Diagnosis); Level of evidence, 3. Methods: Ten orthopedic sports surgeons rated the radiographic healing of 30 knee OCD lesions at 2 time points, a minimum of 1 month apart. First, raters compared pretreatment and 2-year follow-up radiographs on “overall healing” and on 5 subfeatures of healing, including OCD boundary, sclerosis, size, shape, and ossification using a continuous slider scale. “Overall healing” was also rated using a 7-tier ordinal scale. Raters then compared the same 30 pretreatment knee radiographs in a stepwise progression to the 2-, 4-, 7-, 12-, and 24-month follow-up radiographs on “overall healing” using a continuous slider scale. Interrater and intrarater reliability were assessed using intraclass correlations (ICC) derived from a 2-way mixed effects analysis of variance for absolute agreement. Results: Overall healing of the OCD lesions from pretreatment to 2-year follow-up radiographs was rated with excellent interrater reliability (ICC = 0.94) and intrarater reliability (ICC = 0.84) when using a continuous scale. The reliability of the 5 subfeatures of healing was also excellent (interrater ICCs of 0.87-0.89; intrarater ICCs of 0.74-0.84). The 7-tier ordinal scale rating of overall healing had lower interrater (ICC = 0.61) and intrarater (ICC = 0.68) reliability. The overall healing of OCD lesions at the 5 time points up to 24 months had interrater ICCs of 0.81-0.88 and intrarater ICCs of 0.65-0.70. Conclusion: Interrater reliability was excellent when judging the overall healing of OCD femoral condyle lesions on radiographs as well as on 5 specific features of healing on 2-year follow-up radiographs. Continuous scale rating of OCD radiographic healing yielded higher reliability than the ordinal scale rating. Raters showed substantial to excellent agreement of OCD overall radiographic healing measured on a continuous scale at 2, 4, 7, 12, and 24 months after starting treatment.

Purpose To investigate the relation of the at-risk structures (distal femoral physis, lateral collateral ligament, anterolateral ligament, popliteus, and articular cartilage) during all-epiphyseal femoral tunnel drilling. A second purpose was 2-fold: (1) to develop recommendations for tunnel placement and orientation that anatomically reconstruct the anterior cruciate ligament (ACL) while minimizing the risk of injury to these at-risk structures, and (2) to allow for maximal tunnel length to increase the amount of graft in the socket to facilitate healing. Methods Three-dimensional models of 6 skeletally immature knees (aged 7-11 years) were reconstructed from computed tomography and used to simulate all-epiphyseal femoral tunnels. Tunnels began within the ACL footprint and were directed laterally or anterolaterally, with the goal of avoiding injury to at-risk structures. The spatial relation between the ideal tunnel and these structures was evaluated. Full-length tunnels and partial length condyle sockets were simulated in the models using the same trajectories. Results An anterolateral tunnel could be placed to avoid direct injury to lateral structures. The safe zone on the anterolateral aspect of the femur was larger than that of a tunnel with a direct lateral trajectory (median 127 mm 2 vs 83 mm 2 , P = .028). Anterolateral tunnels were longer than direct lateral tunnels (median 30 mm vs 24 mm, P = .041). Safe angles for anterolateral tunnels were 34° to 40° from the posterior condylar axis; direct lateral tunnels were drilled 4° to 9° from the posterior condylar axis. Sockets could be placed without direct injury to structures at risk with either orientation. Conclusions An all-epiphyseal ACL femoral tunnel can be placed without causing direct injury to at-risk structures. A tunnel angled anterolaterally from the ACL origin is longer and has a larger safe zone compared with the direct lateral tunnel. Clinical Relevance The largest safe zone for femoral all-epiphyseal ACL drilling was (1) anterior to the lateral collateral ligament origin, (2) distal to the femoral physis, and (3) proximal to the popliteus tendon origin. A direct lateral tunnel may also be used, but has a smaller safe zone. Sockets or partial length tunnels may have a lower risk of injury to at-risk structures.

Background This study was conducted to evaluate the spatial relationship of the anterior cruciate ligament (ACL) and lateral collateral ligament (LCL) femoral footprint origins in knee specimens from skeletally immature donors as viewed on lateral radiographs. Methods Fourteen cadaver specimens of skeletally immature knees from children between 7 and 11 years old at the time of death were examined through gross dissection. Metallic pins were placed at the center of the ACL and LCL femoral footprints, and computed tomography (CT) scans were performed. Sagittal plane CT images were merged to create a view analogous to an intraoperative C-arm image with overlaid ACL and LCL ligament footprints. Ligament origins were then measured as a percent of the epiphyseal depth (% P-A [posterior-anterior]) and height (% P-D [proximal-distal]). Results The ACL origin was centered at a point located 14% (14% P-A) of the total lateral femoral condyle (LFC) depth from the most posterior aspect of the LFC and 38% (38% P-D) of the LFC height from the most proximal aspect of the posterior physis. The LCL origin was centered at a point 27% P-A and 37% P-D. When viewed on a sagittal CT reconstruction analogous to a perfect lateral intraoperative fluoroscopic view, the ACL footprint origin is posterior and slightly inferior to the LCL origin. Both origins are distal to the distal femoral physis and are posterior to the origin of the popliteus. Conclusions This study demonstrates a consistent relationship between the origin of the ACL and LCL, which may be useful in guiding safe tunnel placement during all-epiphyseal ACL reconstruction in skeletally immature knees. Clinical relevance This anatomic reference can be used intraoperatively to guide and radiographically evaluate ACL tunnel placement while avoiding the LCL origin in skeletally immature patients.

Background: Soccer has one of the highest incidences of anterior cruciate ligament (ACL) injuries for both males and females. Several injury prevention programs have been developed to address this concern. However, an analysis of the pooled effect has yet to be elicited. Purpose: To conduct a systematic review and meta-analysis of ACL and knee injury prevention programs for soccer players, assess the heterogeneity among the studies, and evaluate the reported effectiveness of the prevention programs. Study Design: Systematic review and meta-analysis. Methods: A systematic search of the literature was conducted on PubMed (Medline), Embase, CINAHL, and Central-Cochrane Database. Studies were limited to randomized controlled trials (RCTs) of injury prevention programs specific to the knee and/or ACL in soccer players. The Cochrane Q test and I2 index were independently used to assess heterogeneity among the studies. The pooled risk difference, assessing knee and/or ACL injury rates between intervention and control groups, was calculated by random-effects models with use of the DerSimonian-Laird method. Publication bias was assessed with a funnel plot and Egger weighted regression technique. Results: Nine studies met the inclusion criteria as RCTs. A total of 11,562 athletes were included, of whom 7889 were analyzed for ACL-specific injuries. Moderate heterogeneity was found among studies of knee injury prevention ( P = .041); however, there was insignificant variation found among studies of ACL injury prevention programs ( P = .222). For studies of knee injury prevention programs, the risk ratio was 0.74 (95% CI, 0.55-0.89), and a significant reduction in risk of knee injury was found in the prevention group ( P = .039). For studies of ACL injury prevention programs, the risk ratio was 0.66 (95% CI, 0.33-1.32), and a nonsignificant reduction in risk of ACL injury was found in the prevention group ( P = .238). No evidence of publication bias was found among studies of either knee or ACL injury prevention programs. Conclusion: This systematic review and meta-analysis of ACL and knee injury prevention program studies found a statistically significant reduction in injury risk for knee injuries but did not find a statistically significant reduction of ACL injuries.

Patellar dislocations are common in skeletally immature athletes, and the medial patellofemoral ligament (MPFL) is an important primary restraint to lateral patellar translation. The relationship between the MPFL femoral origin footprint and femoral physis is unclear. The purpose of this study was to evaluate the MPFL femoral origin footprint and its relationship to the femoral physis in skeletally immature anatomic specimens.Six skeletally immature cadaver knee specimens were examined through gross dissection (group A: 1, 11, and 11 mo; and group B: 8, 10, and 11 y). Metallic markers were placed at the center of the MPFL femoral origin footprint. Computed tomography scans for each specimen were analyzed. The MPFL footprint width, and the vertical distances from the center and proximal extent of the MPFL footprint to the medial aspect of the physis were measured.The mean width of the MPFL femoral origin footprint was 0.70 cm (0.48 to 1.09 cm) and 1.12 cm (1.03 to 1.29 cm) for groups A and B, respectively. The mean distance from the center of the MPFL origin footprint to medial aspect of the distal femoral physis was 0.90 cm (0.52 to 1.30 cm) and 0.40 cm (0.00 to 0.86 cm) distal to the physis for groups A and B, respectively. The mean distance from the proximal extent of the MPFL origin footprint to the medial aspect of the femoral physis was -0.55 cm (-0.28 to -1.03 cm) and 0.16 cm (-0.34 to 0.64 cm) for groups A and B, respectively.All subjects were found to have a center of the MPFL origin footprint at or below the physis. The proximal extent of the MPFL origin footprint was found to extend above the physis in the 2 older specimens.The relationship of the MPFL origin footprint to the femoral physis in the skeletally immature is not well understood. These dissections may be useful to surgeons performing MPFL reconstructions in skeletally immature patients.

Background: Most surgeons believe that graft choice for anterior cruciate ligament (ACL) reconstruction is an important factor related to outcome; however, graft choice for revision may be limited due to previously used grafts. Hypotheses: Autograft use would result in increased sports function, increased activity level, and decreased osteoarthritis symptoms (as measured by validated patient-reported outcome instruments). Autograft use would result in decreased graft failure and reoperation rate 2 years after revision ACL reconstruction. Study Design: Cohort study; Level of evidence, 2. Methods: Patients undergoing revision ACL reconstruction were identified and prospectively enrolled by 83 surgeons at 52 sites. Data collected included baseline demographics, surgical technique, pathologic abnormalities, and the results of a series of validated, patient-reported outcome instruments (International Knee Documentation Committee [IKDC], Knee injury and Osteoarthritis Outcome Score [KOOS], Western Ontario and McMaster Universities Osteoarthritis Index [WOMAC], and Marx activity rating score). Patients were followed up at 2 years and asked to complete the identical set of outcome instruments. Incidences of additional surgery and reoperation due to graft failure were also recorded. Multivariate regression models were used to determine the predictors (risk factors) of IKDC, KOOS, WOMAC, Marx scores, graft rerupture, and reoperation rate at 2 years after revision surgery. Results: A total of 1205 patients (697 [58%] males) were enrolled. The median age was 26 years. In 88% of patients, this was their first revision, and 341 patients (28%) were undergoing revision by the surgeon who had performed the previous reconstruction. The median time since last ACL reconstruction was 3.4 years. Revision using an autograft was performed in 583 patients (48%), allograft was used in 590 (49%), and both types were used in 32 (3%). Questionnaire follow-up was obtained for 989 subjects (82%), while telephone follow-up was obtained for 1112 (92%). The IKDC, KOOS, and WOMAC scores (with the exception of the WOMAC stiffness subscale) all significantly improved at 2-year follow-up ( P < .001). In contrast, the 2-year Marx activity score demonstrated a significant decrease from the initial score at enrollment ( P < .001). Graft choice proved to be a significant predictor of 2-year IKDC scores ( P = .017). Specifically, the use of an autograft for revision reconstruction predicted improved score on the IKDC ( P = .045; odds ratio [OR] = 1.31; 95% CI, 1.01-1.70). The use of an autograft predicted an improved score on the KOOS sports and recreation subscale ( P = .037; OR = 1.33; 95% CI, 1.02-1.73). Use of an autograft also predicted improved scores on the KOOS quality of life subscale ( P = .031; OR = 1.33; 95% CI, 1.03-1.73). For the KOOS symptoms and KOOS activities of daily living subscales, graft choice did not predict outcome score. Graft choice was a significant predictor of 2-year Marx activity level scores ( P = .012). Graft rerupture was reported in 37 of 1112 patients (3.3%) by their 2-year follow-up: 24 allografts, 12 autografts, and 1 allograft and autograft. Use of an autograft for revision resulted in patients being 2.78 times less likely to sustain a subsequent graft rupture compared with allograft ( P = .047; 95% CI, 1.01-7.69). Conclusion: Improved sports function and patient-reported outcome measures are obtained when an autograft is used. Additionally, use of an autograft shows a decreased risk in graft rerupture at 2-year follow-up. No differences were noted in rerupture or patient-reported outcomes between soft tissue and bone–patellar tendon–bone grafts. Surgeon education regarding the findings of this study has the potential to improve the results of revision ACL reconstruction.

Background The trochlear groove is the rarest location for osteochondritis dissecans (OCD) of the knee, with only about 50 previously reported cases, most of which were treated before the advent of magnetic resonance imaging (MRI) and modern techniques of cartilage fixation or osteochondral transplantation. The purpose of this multicenter study was to assess the patient presentation and clinical, radiographic, and functional results of treatment for trochlear groove OCD lesions. Methods Hospital records from 5 institutions of the Research in Osteochondritis of the Knee (ROCK) study group were retrospectively reviewed for cases of trochlear groove OCD. Demographics, clinical presentation, diagnosis, treatment, time to pain resolution, and return to sports were recorded. Lesion appearance, size, stability, and time to radiographic healing were evaluated on plain x-rays and MRIs. Results Trochlear groove OCD lesions were evaluated in 24 knees in 21 adolescents (17 male, 4 female), with an average age of 14 years (range, 10 to 18 y). Fifty-four percent (13/24) of the lesions were identifiable on radiographs, and all were identifiable on MRI, 38% of which (9/24) was unstable. One fourth (6/24) of knees had coexistent femoral condyle OCD lesions. Treatment outcomes were evaluated in patients with a minimum of 1-year follow-up (average: 3 y; range: 1 to 12 y) or healing before 1 year. Half of the knees (2/4) treated nonoperatively and two thirds (8/12) treated operatively showed radiographic signs of healing with patients returning to full activity without pain. Operative treatment success rates were as follows: drilling (3/3), fixation (3/3), microfracture (1/2), drilling with subsequent delayed microfracture (1/1), and drilling with fixation (0/3). Conclusions MRI aids in the diagnosis and staging of trochlear groove OCD lesions, as almost one half may not be identifiable on radiographs, and one quarter are associated with OCD lesions in other locations of the same knee. Multiple operative treatments can be used to achieve healing or resolution of symptoms in stable and unstable lesions; however, a larger comparative study is needed to make specific recommendations. Level of evidence Therapeutic Level IV.

Background: Understanding the relationship of the posterior cruciate ligament (PCL) and the lateral collateral ligament (LCL) to the femoral and tibial physes is important to reducing the risk of physeal injury during surgical reconstruction. The purpose of this study was to identify the location of the attachments of the PCL and LCL in skeletally immature cadaveric knee specimens and to determine their position relative to the physes. Methods: Seven skeletally immature cadaveric knee specimens were examined through gross dissection. These specimens were divided into two groups: infants (an age at death of one month for one specimen and eleven months for two specimens) and children (an age at death of eight years for one specimen, ten years for one specimen, and eleven years for two specimens). Metallic markers were placed at the femoral origins of the PCL and LCL and at the tibial insertion of the PCL. Computed tomography (CT) scans were made for each specimen and analyzed with the use of OsiriX imaging software. The width of the PCL tibial insertion footprint and the height of the PCL femoral origin footprint, the distance from the midpoints of the PCL and LCL femoral origin to the distal femoral physis, and the distance from the PCL insertion footprint midpoint to the proximal tibial physis were measured. Results: The mean distance from the midpoint of the femoral origin footprint of the PCL to the femoral physis was 11.1 mm (range, 10.6 to 11.7 mm) and 18.8 mm (range, 18.2 to 19.2 mm) distal to the physis for infants and children, respectively. The mean distance from the midpoint of the tibial insertion footprint of the PCL to the tibial physis was 3.1 mm (range, 0.0 to 5.7 mm) and 5.8 mm (range, 2.5 to 8.9 mm) proximal to the physis for infants and children, respectively. The mean width of the tibial insertion of the PCL was 5.5 mm (range, 1.1 to 8.3 mm) for infants and 10.2 mm (range, 8.4 to 11.9 mm) for children. The mean distance from the midpoint of the femoral origin of the LCL to the femoral physis was 6.3 mm (range, 3.9 to 7.7 mm) and 5.9 mm (range, 0.0 to 10.0 mm) distal to the physis for infants and children, respectively. Conclusions: The relationship of the PCL and LCL attachments to physeal structures has not been well described. We found the midpoints of the PCL and LCL femoral origins at or distal to, and the midpoint of the PCL tibial insertion at or proximal to, the respective physis in all specimens. This study with CT-scan correlation provides unique information on the location of ligament attachments in relation to the physes. Clinical Relevance: A better understanding of the spatial relationship between the PCL and LCL attachments and their respective physes may help guide drill-hole placement during ligament reconstructions and reduce the risk for iatrogenic physeal injury in skeletally immature patients.

Orthopaedic leaders need to create a shared vision and must establish trust, open lines of communication, and buy-in from all team members in order to establish a culture that is supportive of quality improvement. Leaders should encourage teams to follow evidence-based guidelines, reduce variation, take an active role in supply chain processes, and develop new ideas to improve quality and safety of care. With rapidly changing medical and surgical advancements, orthopaedic leaders must continually adapt in the face of evolving challenges.

Background:Rates of anterior cruciate ligament (ACL) reconstruction among pediatric and adolescent patients are increasing. Limited knowledge exists about population-level rates of concomitant meniscal surgery in this age group.Purpose/Hypothesis:This study sought to examine trends in concomitant meniscal procedures and describe short-term complications in pediatric and adolescent patients undergoing ACL reconstruction. We hypothesized that overall meniscal surgery rates are increasing and that the likelihood of performing meniscal repair or meniscectomy is associated with patient- and surgeon-specific factors.Study Design:Cross-sectional study.Methods:We queried ACL procedures in patients younger than 19 years reported by American Board of Orthopaedic Surgery (ABOS) part II examination candidates from 2000 to 2016. Regression models examined associations between patient and surgeon characteristics, year of surgery, follow-up time, meniscal procedure type, and number and type of complications.Results:A total of 9766 cases were identified. Females represented 46% (n = 4468) of included cases. Mean patient age was 16.1 years (SD, 1.62 years; range, 0-18 years). The rate of concomitant ACL-meniscal procedures increased from the years 2000 to 2016 (49%-60%; P = .005). Surgeons with sports medicine (+7.0%) or pediatric orthopaedic fellowship (+6.6%) training had a higher likelihood of reporting a concomitant ACL-meniscal procedure ( P = .003 and .006, respectively). Sports medicine–trained surgeons were more likely to perform meniscal repair compared with meniscectomy (+3.0%; P = .016). Younger patient age was associated with increased likelihood of undergoing meniscal repair compared with meniscectomy. Overall reported complication rate was 12.8%. Notable reported complications included infection (1.61%), arthrofibrosis (1.14%), and deep venous thrombosis or pulmonary embolism (0.11%). Sports medicine and pediatric orthopaedic fellowship training was associated with higher rates of reporting postoperative stiffness and/or arthrofibrosis.Conclusion:Among ABOS part II candidates, concomitant ACL-meniscal surgery has become more common than isolated ACL procedures. Procedures involving sports medicine fellowship–trained surgeons and younger patients were associated with increased rates of meniscal repair compared with meniscectomy. Pediatric orthopaedic and sports medicine training was associated with a greater likelihood of being involved in a concomitant ACL-meniscal procedure of any kind, and surgeons with such training also reported a higher incidence of postoperative stiffness and/or arthrofibrosis in patients.

Background: Tibial spine fractures, although relatively rare, account for a substantial proportion of pediatric knee injuries with effusions and can have significant complications. Meyers and McKeever type II fractures are displaced anteriorly with an intact posterior hinge. Whether this subtype of pediatric tibial spine fracture should be treated operatively or nonoperatively remains controversial. Surgical delay is associated with an increased risk of arthrofibrosis; thus, prompt treatment decision making is imperative. Purpose: To assess for variability among pediatric orthopaedic surgeons when treating pediatric type II tibial spine fractures. Study Design: Cross-sectional study. Methods: A discrete choice experiment was conducted to determine the patient and injury attributes that influence the management choice. A convenience sample of 20 pediatric orthopaedic surgeons reviewed 40 case vignettes, including physis-blinded radiographs displaying displaced fractures and a description of the patient’s sex, age, mechanism of injury, and predominant sport. Surgeons were asked whether they would treat the fracture operatively or nonoperatively. A mixed-effects model was then used to determine the patient attributes most likely to influence the surgeon’s decision, as well as surgeon training background, years in practice, and risk-taking behavior. Results: The majority of respondents selected operative treatment for 85% of the presented cases. The degree of fracture displacement was the only attribute significantly associated with treatment choice ( P < .001). Surgeons were 28% more likely to treat the fracture operatively with each additional millimeter of displacement of fracture fragment. Over 64% of surgeons chose to treat operatively when the fracture fragment was displaced by ≥3.5 mm. Significant variation in surgeon’s propensity for operative treatment of this fracture was observed ( P = .01). Surgeon training, years in practice, and risk-taking scores were not associated with the respondent’s preference for surgical treatment. Conclusion: There was substantial variation among pediatric orthopaedic surgeons when treating type II tibial spine fractures. The decision to operate was based on the degree of fracture displacement. Identifying current treatment preferences among surgeons given different patient factors can highlight current variation in practice patterns and direct efforts toward promoting the most optimal treatment strategies for controversial type II tibial spine fractures.

Background: Meniscal injuries in the skeletally immature have been increasingly reported. Many meniscal repair surgeries involve the approximation of the meniscus tissue to the peripheral meniscus capsule. This peripheral fixation may not be ideal for some meniscus tear patterns, and may contribute to ‘peripheralization’ of the meniscus during the healing process, which may alter the weight bearing distribution function of the meniscus/articular cartilage complex. Surgical procedures that do not periperalize the meniscus are being developed, which may better replicate the normal meniscus anatomy. Purpose: The primary purpose of this study was to evaluate the coronary ligament attachments of the meniscus, and how this may influence further development of anatomic repair techniques and implants to address meniscus injury. The secondary purpose of this study was to determine the distance between the tibial insertion of the coronary ligament and the proximal tibial physis. Methods: 10 skeletally immature knee cadaver specimens between the ages of 3 months and 11 years (3 female, 7 male) were included in this study. Prior to CT, pins were placed in the tibias marking the coronary ligament insertion at designated points surrounding both the medial and lateral menisci (Figure 1). Using OsiriX, a medical imaging software, the distances between the proximal tibial physis and the coronary ligament insertion sites were measured at 10 points (5 lateral: anterior root, 12 o’clock, 3/9 o’clock, 6 o’clock, and posterior root, and 5 medial: anterior root, 12 o’clock, 3/9 o’clock, 6 o’clock, and posterior root). Axial view was used confirm proper pin measurement and the measurements were gathered in either the sagittal and coronal view depending on the pin’s placement. The specimen were divided into two groups for analysis- Group 1: ages 3 months- 2 years, Group 2: ages 10-11 years. Results: Medial Meniscus The average distance from the proximal tibial physis to the posterior medial root of the coronary ligament was 0.48 ± 0.08 cm and 1.02 ± 0.10 cm for Group 1 and Group 2, respectively. The average distance from the physis and the 6 o’clock pin was 0.37 ± 0.19 cm and 0.78 ± 0.23 cm. The average distance from the physis and the 3/9 o’clock pin was 0.32 ± 0.13 cm and 0.73 ± 0.22 cm. The average distance from the physis to the 12 o’clock pin was 0.14 ± 0.22 cm and 0.65 ± 0.45 cm. The average distance from the physis to the anterior pin was 0.21 ± 0.30 cm and 1.01 ± 0.62 cm. Lateral Meniscus The average distance from the proximal tibial physis to the posterior lateral root of the coronary ligament was 0.48 ± 0.11 cm and 1.62 ± 0.29 cm for Group 1 and Group 2, respectively. The average distance from the physis and the 6 o’clock pin was 0.38 ± 0.16 cm and 1.72 ± 0.25 cm. The average distance from the physis and the 3/9 o’clock pin was 0.17 ± 0.15 cm and 0.1.41 ± 0.19 cm. The average distance from the physis to the 12 o’clock pin was -0.04 ± 0.20 cm and 0.60 ± 0.14 cm. The average distance from the physis to the anterior pin was 0.16 ± 0.07 cm and 0.31 ± 0.16 cm. Conclusions: Our results show an increase in the distance between the proximal tibial physis and the insertion points of the coronary ligament as age increases. For all measurements, medial and lateral, Group 1 (the younger specimen’s) tibial insertion of the coronary ligament was less than 1 cm away from the physis. Group 2’s coronary ligament insertion points were further away from the physeal line, however still less than 2 cm away, and sometimes even as close as Clinical Significance: This study of pediatric cadaveric specimens allowed for direct visualization of the coronary ligament anatomy on the tibia. This information is clinically significant as it detailed the developmental pattern of coronary ligament anatomy in pediatrics and can be used by surgeons performing meniscal injury reconstructions and repairs in patients with open physes. [Figure: see text]

Background: In skeletally immature patients, the MPFL femoral origin as near or below the physis in most age groups. Although MPFL reconstruction procedures that employ patella drill holes facilitate graft tension adjustment, recent research demonstrates significant risk of patella fractures if patella drill holes are utilized. For this reason, the use of patella drill holes may be best avoided, but this technical alteration makes graft tension fixation more challenging during MPFL reconstruction in the skeletally immature. The purpose of this study was to evaluate the feasibility of developing a physeal respecting femoral drill for the MPFL origin with surgical model simulation, which allows for graft tensioning during MPFL reconstruction. Methods: Pediatric cadaveric specimens (n=5) were dissected by a group of fellowship trained pediatric and/or sports orthopaedic surgeons, and these specimens were then subject to CT Scans for the creation of 3D models. Specimens, aged 7, 9, 10, 11 and 11 years, were used to develop surgical simulations. CT Scans were loaded into Osyrix, converted to appropriate file structure, and then 3D models were loaded into Blender (Stichting Blender Foundation, Buikslotermeerplein 161, 1025 ETAmsterdam, the Netherlands). These models were used to evaluate 3D models of the knee, with placement of medial femoral condyle drill holes starting at the MPFL femoral origin, and entering the joint just anterior to the PCL femoral origin. The anatomic goals of the surgical simulation include: 1. Place drill hole at the MPFL origin on the femur. 2 Enter the intercondylar notch region of the femur anterior to the PCL origin allowing for arthroscopic visualization. 3. avoiding the articular cartilage on the medial femoral condyle. 4. Avoid the femoral physis throughout the course of drilling from the femoral MPFL Origin point to the entry location into the intercondylar notch. In the specimens, a full length drill hole was placed with either a 4 or 5 mm drill hole. Results: All specimens were subject to the surgical modeling and simulated drill hole placement. In each case, a drill hole was successfully placed meeting all the goals of the simulation: 1. Starting Point at MPFL, 2. Exit point anterior the PCL origin, 3. Exit point posterior to the articular cartilage, and 4. Avoidance of direct physeal injury. Figures 1 and 2. Conclusion: Setting graft tension during MPFL reconstruction is one of the significant technical challenges during MPFL reconstruction, and appropriate graft position and tension may be the most critical elements of successful MPFL reconstruction. Historically, graft tension has been set on the patella, using drill holes for the MPFL attachment point on the patella, but this technique has been associated with patella fractures. In order to allow for adjustment of graft tension on the femoral side of the MPFL graft during surgical reconstruction, a surgical simulation was developed to confirm the anatomic appropriateness and safety of placement of femoral drill holes which allow for adjustment of graft tension. This surgical simulation model confirms that MPFL femoral origin anatomy can be reproduced with injury to the physis, the PCL, or the articular cartilage of the femoral condyle. This drill hole and graft can be visualized arthroscopically and allow for appropriate graft tensioning during the procedure. [Figure: see text][Figure: see text]

Background: To describe the results and extra-physeal position of a pediatric distal femoral trochleoplasty in a pediatric cadaveric model. Methods: Eight pediatric cadaveric specimens (mean maturity: 7.75 years, range 4-11) were used to model a distal femoral anterolateral metaphyseal osteotomy immediately proximal to the physis. A standardized 4 mm wedge was placed at the distal end of an anterior cortical shingle; created by an osteotomy 3.25 mm below the anterior cortex (range 2.5 – 4.4), with a transverse corticotomy just proximal to the physis, and hinged 25.5 mm proximally (range 21.9-28.1). The specimens were evaluated with multi-planar micro-CT scans (0.67 mm) pre and post-osteotomy. Lateral cortical elevation, the pre and post sulcus angle of the anterior supra-trochlear metaphysis, distance from distal elevated margin of the osteotomy to the superior edge of the trochlear cartilage, and distance from the distal margin of the osteotomy to the superior edge of the physis were evaluated. Results: The supra-physeal trochleoplasty elevated the lateral cortex an average of 3.26 mm (range 2.8-3.9). The resultant mean angle of the supra-trochlear metaphyseal sulcus was changed by 15.25° (range 8° -21°) (pConclusion: A technique for an extra-physeal, metaphyseal, distal femoral trochleoplasty resulted in alterations to the anterior femoral cortex that may serve as deterrents to lateral patellar translation. Lateral cortical elevation immediately superior to the trochlea may serve as a guide for centralizing patellar motion during early flexion in the setting of patella alta and trochlear dysplasia that is not uncommon in pediatric lateral patellar instability. A pediatric cadaveric model demonstrated changes in close proximity to the superior entrance of the femoral trochlea, while avoiding injury to the distal femoral physis. Significance: A supra-trochlear, lateral metaphyseal elevating osteotomy may be feasible and merit further study as an option for the treatment of lateral patellar instability in the skeletally immature.

INTRODUCTION: Anterior cruciate ligament (ACL) reconstruction is one of the most common procedures performed in adolescents. Similarly, the rate of ACL reconstructions performed in pediatric patients has been increasing, and this population has the highest rate of primary and revision ACL Surgery. The purpose of this study was to review data on ACL reconstructions performed in patients under the age of 19 years that were submitted to the American Board of Orthopaedic Surgeons (ABOS) Part 2 examination to evaluate post-operative complications and trends over time in applicant fellowship training. METHODS: A query to the ABOS SCRIBE database was submitted for all ACL reconstructions performed in patients less than 19 years old. The database query was based on ICD-9 and ICD-10 diagnostic codes submitted by each applicant. Data included geographic region, fellowship training of the applicant, exam subspecialty, and reported complications. A subgroup analysis of complications was also performed in patients less than 15 years compared to those 15-18 and amongst different applicants based on fellowship training. RESULTS: From 2000 – 2016, 9,767 ACL reconstructions were performed by candidates taking Part 2 of the ABOS board certification process. The mean age at surgery was 16 years (reported age range 0-18) and a meniscus procedure was performed in 57% of cases. There was a 41% increase in ACL reconstructions in those under the age of 15 years between 2000 and 2016. In each age group, the incidence of ACL reconstruction in males was higher than in females (ratio 5:4) except in those 12 and 13 years old whereby the incidence was higher in females (ratio 2:1). A majority (70.5%) of ACL reconstructions were performed by candidates with a sports medicine fellowship. In patients less than 15 years old 24.5% of reconstructions were performed by candidates with a pediatric or dual pediatric and sports medicine fellowship training. The overall complication rate was 13.6% with 0.4% anesthetic related complication (0.2% related to regional anesthesia). The reoperation rate was 0.8% and the readmission rate was 0.5%. Twelve patients (0.14%) sustained a venous thromboembolic event (6 deep vein thrombosis and 6 pulmonary embolism). A majority of complications (10.83%) were related to the surgery. The most common surgery related complications were infection (1.51%) and arthrofibrosis (1.3%). The overall incidence of reported complications was not statistically different between those with sports (13.7%), pediatric (16.3%), or both sports and pediatric fellowships (17.5%). Differences in specific complications were noted when comparing those with only pediatric training and those with only sports medicine fellowship training including graft related problems (1.9% vs. 0.7%, p=0.001, respectively) and nerve palsy/injury (1.9% vs. 0.6%, pCONCLUSION/DISCUSSION: ACL reconstruction in the adolescent and pediatric age groups are primarily performed by candidates with a sports medicine fellowship. Complications rates between candidates reporting either sports medicine or pediatric fellowship training are overall comparable. Graft related complication and nerve palsy/injury were lower in those with sports medicine fellowships and both pediatric and sports medicine fellowships suggesting that additional training in sports medicine or arthroscopy may help minimize those complications. Longitudinal studies evaluating long term risks and complications after pediatric/adolescent ACL reconstruction are needed.

This article was updated on June 30, 2015, because of a previous error. The name of one of the authors, which had previously read “Gregory D. Meyer, PhD,” has been corrected to read “Gregory D. Myer, PhD.” An erratum has been published: J Bone Joint Surg Am. 2015 Aug 5;97(15):e57. The AAOS Evidence-Based Guideline on Management of Anterior Cruciate Ligament Injuries includes both diagnosis and treatment. This clinical practice guideline has been endorsed by the National Academy of Sports Medicine (NASM), the American Orthopaedic Society for Sports Medicine (AOSSM), the National Athletic Trainers’ Association (NATA), and the American Academy of Physical Medicine and Rehabilitation (AAPM&R). This brief summary of the AAOS Clinical Practice Guideline contains a list of the recommendations and the rating of strength based on the quality of the supporting evidence. Discussion of how each recommendation was developed and the complete evidence report are contained in the full guideline at www.aaos.org/guidelines. ### ACL HISTORY AND PHYSICAL Strong evidence supports that the practitioner should obtain a relevant history and perform a musculoskeletal exam of the lower extremities, because these are effective diagnostic tools for ACL injury. Strength of Recommendation: Strong ★★★★ ### ACL RADIOGRAPHS In the absence of reliable evidence, it is the opinion of …

Although many etiological theories have been proposed for osteochondritis dissecans (OCD), its etiology remains unclear. Histological analysis of the articular cartilage and subchondral bone tissues of OCD lesions can provide useful information about the cellular changes and progression of OCD. Previous research is predominantly comprised of retrospective clinical studies from which limited conclusions can be drawn.The purposes of this study were threefold: (1) Is osteonecrosis a consistent finding in OCD biopsy specimens? (2) Is normal articular cartilage a consistent finding in OCD biopsy specimens? (3) Do histological studies propose an etiology for OCD based on the tissue findings?We searched the PubMed, Embase, and CINAHL databases for studies that conducted histological analyses of OCD lesions of the knee and identified 1560 articles. Of these, 11 met our inclusion criteria: a study of OCD lesions about the knee, published in the English language, and performed a histological analysis of subchondral bone and articular cartilage. These 11 studies were assessed for an etiology proposed in the study based on the study findings.Seven of 11 studies reported subchondral bone necrosis. Four studies reported normal articular cartilage, two studies reported degenerated or irregular articular cartilage, and five studies found a combination of normal and degenerated or irregular articular cartilage. Five studies proposed trauma or repetitive stress and two studies proposed poor blood supply as possible etiologies.We found limited research on histological analysis of OCD lesions of the knee. Future studies with consistent methodology are necessary to draw major conclusions about the histology and progression of OCD lesions. Inconsistent histologic findings have resulted in a lack of consensus regarding the presence of osteonecrosis, whether the necrosis is primary or secondary, the association of cartilage degeneration, and the etiology of OCD. Such studies could use a standardized grading system to allow better comparison of findings.

Background: As value becomes a larger component of heath care decision making, cost data can be evaluated for regional and physician variation. Value is determined by outcome divided by cost, and reducing cost increases value for patients. “Third-party spend” items are individual selections by surgeons used to perform procedures. Cost data for third-party spend items provide surgeons and hospitals with important information regarding care value, potential cost-saving opportunities, and the total cost of ownership of specific clinical decisions. Purpose: To perform a cost review of isolated rotator cuff repair within a regional 7-hospital system and to document procedure cost variation among operating surgeons. Study Design: Economic and decision analysis; Level of evidence, 4. Methods: Current Procedural Terminology (CPT) codes were used to retrospectively identify subjects who received an isolated rotator cuff repair within a 7-hospital system. Cost data were collected for clinically sensitive third-party spend items and divided into 4 cost groups: (1) suture anchors, (2) suture-passing devices and needles, (3) sutures used for cuff repair, and (4) disposable tools or instruments. Results: A total of 62 isolated rotator cuff repairs were performed by 17 surgeons over a 13-month period. The total cost per case for clinically sensitive third-party spend items (in 2015 US dollars) ranged from $293 to $3752 (mean, $1826). Four surgeons had a mean procedure cost that was higher than the data set mean procedure cost. The cost of an individual suture anchor ranged from $75 to $1775 (mean, $403). One disposable suture passer was used, which cost $140. The cost of passing needles ranged from $140 to $995 (mean, $468). The cost per repair suture (used to repair cuff tears) varied from $18 to $298 (mean, $61). The mean suture (used to close wounds) cost per case was $81 (range, $0-$454). A total of 316 tools or disposable instruments were used, costing $1 to $1573 per case (mean, $624). Conclusion: This study demonstrates significant cost variation with respect to cost per case and cost of individual items used during isolated rotator cuff repair. Suture anchors represent the most expensive and variable surgeon-directed cost. The wide cost variation seen in all cost categories illustrates both the effect of surgeon choice in procedure cost and the opportunity for significant cost savings in cases of isolated rotator cuff repair. Engaging surgeons in discussion on cost can positively influence the value of care provided to patients if costs can be reduced without affecting the quality of patient outcomes.

Anterior cruciate ligament (ACL) reconstruction failure rates are highest in youth athletes. The role of the anterolateral ligament in rotational knee stability is of increasing interest, and several centers are exploring combined ACL and anterolateral ligament reconstruction for these young patients. Literature on the anterolateral ligament of the knee is sparse in regard to the pediatric population. A single study on specimens younger than age 5 years demonstrated the presence of the anterolateral ligament in only one of eight specimens; therefore, much about the prevalence and anatomy of the anterolateral ligament in pediatric specimens remains unknown. We sought to (1) investigate the presence or absence of the anterolateral ligament in prepubescent anatomic specimens; (2) describe the anatomic relationship of the anterolateral ligament to the lateral collateral ligament; and (3) describe the anatomic relationship between the anterolateral ligament and the physis. Fourteen skeletally immature knee specimens (median age, 8 years; range, 7–11 years) were dissected (12 male, two female specimens). The posterolateral structures were identified in all specimens, including the lateral collateral ligament and popliteus tendon. The presence or absence of the anterolateral ligament was documented in each specimen, along with origin, insertion, and dimensions, when applicable. The relationship of the anterolateral ligament origin to the lateral collateral ligament origin was recorded. The anterolateral ligament was identified in nine of 14 specimens. The tibial attachment point was consistently located in the same region on the proximal tibia, between the fibular head and Gerdy’s tubercle; however, the femoral origin of the anterolateral ligament showed considerable variation with respect to the lateral collateral ligament origin. The median femoral origin of the anterolateral ligament was 10 mm (first interquartile 6 mm, third interquartile 13) distal to the distal femoral physis, whereas its median insertion was 9 mm (first interquartile 5 mm, third interquartile 11 mm) proximal to the proximal tibial physis. The frequency of the anterolateral ligament in pediatric specimens we observed was much lower than other studies on adult specimens; future studies might further investigate the prevalence, development, and functional role of the anterolateral ligament of the knee. This study expands our understanding of the anterolateral ligament and provides important anatomic information to surgeons considering anterolateral ligament reconstruction concomitantly with primary or revision ACL reconstruction in pediatric athletes.

The AAOS Evidence-Based Guideline on Management of Carpal Tunnel Syndrome (CTS) includes both diagnosis and treatment. This clinical practice guideline has been endorsed by the American Society for Surgery of the Hand (ASSH), the American College of Radiology (ACR), the American College of Surgeons (ACS), and the American Society of Plastic Surgeons (ASPS). This brief summary of the AAOS Clinical Practice Guideline contains a list of the recommendations and the rating of strength based on the quality of the supporting evidence. Discussion of how each recommendation was developed and the complete evidence report are contained in the full guideline at www.aaos.org/guidelines. ### OBSERVATION Strong evidence supports that thenar atrophy is strongly associated with ruling in CTS but poorly associated with ruling out CTS. Strength of Recommendation: Strong ★★★★ ### PHYSICAL SIGNS Strong evidence supports not using the Phalen test, Tinel sign, or upper limb neurodynamic/nerve test (ULNT) criterion A/B as independent physical examination maneuvers to diagnose CTS, because alone, each has a poor or weak association with ruling in or ruling out CTS. Strength of Recommendation: Strong ★★★★ ### MANEUVERS Moderate evidence supports not using the following as independent physical examination maneuvers to diagnose CTS, because alone, each has a poor or weak association with ruling in or ruling out CTS

Background: Soccer has one of the highest rates of ankle injury in sports for both males and females. Several injury prevention programs have been developed to address this concern. The purposes of this study were to conduct a meta-analysis of ankle injury prevention programs for soccer players, assess the heterogeneity among the studies, and evaluate the reported effectiveness of the prevention programs. Methods: A systematic search of the literature was conducted in PubMed (MEDLINE), Embase, CINAHL (Cumulative Index to Nursing and Allied Health), and the Cochrane Central Register of Controlled Trials (CENTRAL) database. Studies were limited to clinical investigations of injury prevention programs specific to the ankle in soccer players. Title, abstract, and full-text review were utilized to identify articles that met the inclusion criteria. The Cochrane Q test and I2 index were independently used to assess heterogeneity among the studies. Sensitivity analyses were performed to assess heterogeneity. The pooled risk difference was calculated by random-effects models with use of the DerSimonian-Laird method. Publication bias was assessed with a funnel plot and Egger weighted regression technique. Results: Ten studies met the inclusion criteria as randomized controlled trials. A total of 4,121 female and male soccer athletes were analyzed for ankle injuries. Significant heterogeneity was found among studies of ankle injury prevention (p = 0.002), with an I2 index of 65.2%. For studies of ankle injury prevention programs, the risk ratio was 0.60 (95% confidence interval, 0.40 to 0.92) and a significant reduction in the risk of ankle injury was found in the prevention group (p = 0.002). No evidence of publication bias was found among the included studies. Conclusions: This meta-analysis of studies regarding ankle injury prevention programs identified a significant reduction in the risk of ankle injury. Future high-quality research designs with a low risk of bias are necessary to further evaluate the effectiveness of specific exercises and the optimal timing and age at intervention for the prevention of ankle injuries in the athletic soccer player. Level of Evidence: Therapeutic Level I. See Instructions for Authors for a complete description of levels of evidence.

Background: Young athletes sustain patellar dislocations in a variety of sports. The medial patellofemoral ligament (MPFL) is a critical structure that functions as an anatomic checkrein to help prevent lateral patellar dislocation. Reconstruction of this ligament is challenging in patients with open physes because of concerns about iatrogenic damage to the femoral physis. Purpose: To evaluate the relationship of the distal femoral physis and the MPFL. Study Design: Descriptive laboratory study. Methods: In 15 cadaveric, pediatric knees (age, 7-11 years), markers were placed at the proximal/distal limits of the MPFL femoral attachment and were evaluated with computed tomography. The distance from the MPFL attachment midpoint to the most medial aspect of the distal femoral physis was measured. Results: The mean femoral width of the MPFL was 8.1 mm (range, 4.3-13.8 mm). The femoral MPFL midpoint was distal to the femoral physis in 11 specimens and proximal to the physis in 4 specimens. The most proximal portion of the MPFL femoral attachment extended above the medial physis in 7, was at the physis in 5, and was below the physis in 3 specimens. One specimen had the entire MPFL femoral attachment above the physis. For knees with the MPFL midpoint above the medial physis, the distance between the center of the MPFL and physis was 3.3 mm (range, 0.3-7.1 mm). For knees with the MPFL below the medial physis, the distance between the center of the MPFL and physis was −6.8 mm (range, −0.7 to −22.0 mm). Conclusion: The relationship of the femoral attachment of the MPFL and the medial femoral physis shows some anatomic variation. In all cases, the MPFL is close to the medial femoral physis, but the midpoint of the MPFL is at, slightly above, or slightly below the physis. Clinical Relevance: The relationship of the MPFL femoral attachment footprint to the femoral physis in the skeletally immature patient is not well understood, and access to pediatric cadaveric tissue is very limited. This small series demonstrates that there is considerable variation in the relationship between the MPFL and distal femoral physis. This anatomic information may guide MPFL reconstruction technique in young patients and reduce the risk of iatrogenic physeal arrest on the femur.

Background:Several systems have been proposed for classifying osteochondritis dissecans (OCD) of the knee during surgical evaluation. No single classification includes mutually exclusive categories that capture all of the salient features of stability, chondral fissuring, and fragment detachment. Furthermore, no study has assessed the reliability of these classification systems.Purpose:To determine the intra- and interobserver reliability of a novel, comprehensive arthroscopic classification system with mutually exclusive OCD lesion types.Study Design:Cohort study (diagnosis); Level of evidence, 3.Methods:The Research in OsteoChondritis of the Knee (ROCK) study group developed a classification system for arthroscopic evaluation of OCD of the knee that includes 6 arthroscopic categories—3 immobile types and 3 mobile types. To optimize comprehensibility and applicability, each was developed with a memorable name, a brief description, a line diagram corresponding to the archetypal arthroscopic appearance, and an arthroscopic photograph depicting this archetype. Thirty representative arthroscopic videos were evaluated by 10 orthopaedic surgeon raters, who classified each lesion. After 4 weeks, the raters again classified the OCD lesions depicted in the 30 videos in a new, randomly selected order. Reliability was assessed via the intraclass correlation coefficient (ICC).Results:The interobserver reliability of this novel arthroscopy classification was estimated by an ICC of 0.94 (95% CI, 0.91-0.97) for the first round and 0.95 (95% CI, 0.93-0.98) for the second round. According to the standards for the magnitude of the reliability coefficient of Altman, these ICCs indicate that interobserver reliability was very good. The intraobserver reliability was estimated by an ICC of 0.96 (95% CI, 0.95-0.97), which indicates that the intraobserver reliability was similarly very good.Conclusion:The ROCK OCD knee arthroscopy classification system demonstrated excellent intra- and interobserver reliability. In light of this reliability, this classification system may be used clinically and to facilitate future research, including multicenter studies for OCD.

This article was updated on May 4, 2016, because of a previous error. On page 689, under the “DELAY TKA” heading, the text had previously read “Moderate evidence supports that a 5-month delay to total knee arthroplasty (TKA) does not worsen outcomes.” The text now reads “Moderate evidence supports that an 8-month delay to total knee arthroplasty (TKA) does not worsen outcomes.” An erratum has been published: J Bone Joint Surg Am. 2016 June 15;98(12):e53. The AAOS Evidence-Based Guideline on Surgical Management of Osteoarthritis of the Knee includes both diagnosis and treatment. This clinical practice guideline has been endorsed by the Arthroscopy Association of North America (AANA) and the Society of Military Orthopaedic Surgeons (SOMOS). This brief summary of the AAOS Clinical Practice Guideline contains a list of the recommendations and the rating of strength based on the quality of the supporting evidence. Discussion of how each recommendation was developed and the complete evidence report are contained in the full guideline at http://www.aaos.org/Quality/Clinical\_Practice\_Guidelines/Clinical\_Practice\_Guidelines/. ### BMI AS A RISK FACTOR Strong evidence supports that obese patients have less improvement in outcomes with total knee arthroplasty (TKA). Strength of Recommendation: Strong ★★★★ ### DIABETES AS A RISK FACTOR Moderate evidence supports that patients with diabetes are at higher risk for complications with total knee arthroplasty (TKA). Strength of Recommendation: Moderate ★★★☆ ### CHRONIC PAIN AS A RISK FACTOR Moderate evidence supports that patients with select chronic pain conditions have less improvement in patient reported outcomes with TKA. Strength of Recommendation: Moderate ★★★☆ ### DEPRESSION/ANXIETY AS A RISK FACTOR Limited evidence supports that patients with depression and/or anxiety symptoms have less improvement in patient reported outcomes with total knee arthroplasty (TKA). Strength of Recommendation: Limited ★★☆☆ ### CIRRHOSIS/HEPATITIS C AS A RISK FACTOR Limited evidence supports that patients with cirrhosis …

The passage of the Medicare Access and Children's Health Insurance Program Reauthorization Act of 2015 (HR 2) helps ensure patient access to care and stable physician reimbursement for the near future. HR 2's underlying theme is the improvement of value to address the unsustainable rise in national healthcare spending. Quality improvement and performance improvement, which affect outcomes and costs as well as address variation, are the keys to improve the value of orthopaedic healthcare delivery. Orthopaedic surgeons should examine quality and performance strategies as well as several examples before they begin to implement these processes to improve quality and performance in their practices.

The importance and benefits of exercise are well documented. With childhood obesity rates rising in most developed countries, encouraging outdoor play and sports participation may be one of several solutions for this problem. However, with the increased youth sport participation seen over the past 10 years, there has also been a need to monitor the risks of participation within this unique population. Unfortunately, only a few well-designed epidemiologic surveillance studies have been conducted thus far. The pediatric and adolescent population is unique in that their skeletal system is still maturing, and thus, they may be susceptible to unique injury patterns and injury frequency. The frequency and severity of sports injuries can differ based on the type of exposure (competition vs practice), sport, gender, and age. Recording these variables is important to accurately determine risk and obtain reliable epidemiologic data. To do this, standard definitions for injury and exposure should be established and widely accepted. Standardization of injury reporting will allow comparison of results across studies so the associated factors can be more thoroughly explored. The purpose of this article is to review the types and patterns of knee and anterior cruciate ligament (ACL) injuries for youth sports based upon recent research. Much of this review is based upon the extensive research of Comstock et al using data compiled from the National High School Sports-Related Injury Surveillance Study. 1 This article will focus on the

Background Lawnmower injuries remain a preventable cause of serious morbidity and even mortality in children. We aimed to characterize lawnmower injuries in children and to describe reported mechanisms through a review of the literature to better understand these injuries and their prevention. Methods The Embase and MEDLINE databases were queried for studies pertaining to pediatric lawnmower injuries, along with manual searching of references of included studies and Google Scholar searches. Reviews and case reports were excluded. Studies relating to lawnmower injuries were broadly included to ensure capture of the relevant studies. Studies with both adult and pediatric data were included if pediatric data were granular and available for separate analysis. Results Thirteen studies met inclusion criteria: 8 single-center series and 5 national database studies. Age of injury was bimodal with peak frequencies at ages 3 and 16 years. National studies estimated a mean of 11.2 injuries per 100,000 children, with 5% to 8% of patients hospitalized. Analysis of both single-center series and national database studies revealed 3 major mechanisms of injury: blade injuries, projectile injuries, and burn injuries. Blade injuries resulted in higher morbidity, with a greater need for operative management, amputation, and longer length of hospitalization. Similarly, rider mowers posed a greater injury risk than push mowers. Conclusions This systematic review of lawnmower injuries in children identified patterns and mechanisms of injuries across the literature that may serve to educate parents, policy-makers, and health-care providers as well as provide data to develop and improve prevention strategies.

PURPOSE The purpose of this study is to identify demographic factors, comorbid conditions, and procedure approaches associated with higher total hospital resources consumed by Medicare beneficiaries (MBs) during a primary 1- or 2-level lumbar spinal fusion (1-2 LLF). METHODS This retrospective study examined the calendar year 2014 Medicare inpatient standard analytical files (IPSAF) linked data for hospital claims. There were 43,117 hospitalizations where a Medicare beneficiary survived for at least 90 days following a 1-2 LLF hospitalization during the first three quarters of 2014. Multi-variable regression cost equations were estimated controlling for 8 demographic characteristics, the presence of 31 comorbid conditions, and the fusion approach or a combination of fusion approaches used during the 1-2 LLF procedures. Control variables were considered a statistically significant predictor of hospital resource use if the associated p-value was less than .01. RESULTS Overall, the majority of MBs undergoing a 1-2 LLF were white (89.5%), female (59.1%) and between 65 and 74 years of age (53.2%). Average total cost of hospital resources consumed during the initial hospitalization was $27,182±$15,569. The regression results estimated that the y-intercept for total hospital resource cost to be $21,881. The resource cost equation indicates that, compared to MBs age 80 and older, hospital costs were significantly higher (between $1,529 and $2,238) in each of the other four age groups. In addition, MBs who were non-white had significant higher estimated index hospital cost. Furthermore, 14 comorbid conditions were associated with higher incremental hospital cost and four comorbid conditions had estimated incremental cost exceeding $10,000 [malnutrition ($19,243), malignant tumor ($14,780), bone infection ($13,025), and benign tumor ($11,875)]. On the other hand, six comorbid conditions were estimated to be associated with lower hospital resource utilization. The lowest hospital resource utilization was associated with a posterior column/posterior approach technique. All other fusion approaches and combinations thereof significantly increased the estimated incremental hospital resource utilization with the anterior/posterior/anterior column/posterior approach being the most costly with an incremental increase of $26,515. CONCLUSIONS There is increasing interest in understanding the resources utilized during the hospitalization for high volume Medicare procedures such and 1-2 LLF. This study identifies 22 demographic, comorbid conditions, and fusion approaches estimated to increase incremental hospital cost by over 5% during the MBs index hospitalization. As the Medicare program continues to place hospitals at risk for the care MBs receive post discharge, it will become increasingly important to determine if care paths can be developed for MBs with selected comorbid conditions that reduce the incremental resources they are currently consuming during the initial procedure. FDA DEVICE/DRUG STATUS This abstract does not discuss or include any applicable devices or drugs.

Purpose The purpose of this study was to determine the origin of the medial patellofemoral ligament (MPFL) relative to the distal femoral physis by use of an indirect radiologic method. Methods Twenty radiographs from adolescent male and female subjects (10 samples from each group) were used. The subjects studied were all skeletally immature, with an open distal femoral physis. The radiographic technique described by Schottle et al. was used to identify the origin of the MPFL. Imaging software was used to determine the approximate distance of the MPFL origin relative to the open growth plate of the subjects involved. Results In all 20 radiographs the medial physis was found to be distal to the average MPFL insertion point. The mean location for the female physis was 2.7 ± 1.1 mm distal to the MPFL origin. The mean location for the male physis was 4.6 ± 2.4 mm distal to the MPFL origin. Conclusions Based on an indirect radiographic technique, we found that the origin of the MPFL is just proximal to the femoral physis. Clinical Relevance: This information may be useful when planning medial retinacular surgical procedures in skeletally immature athletes to help avoid clinically significant physeal injury.

Background: Anterior cruciate ligament (ACL) ruptures have become increasingly common in pediatric and adolescent athletes. While multiple methods exist, all-epiphyseal ACL reconstruction is a popular technique in the skeletally immature patient. Given the high rate of reruptures in this population and the increasing number of commercially available fixation devices, biomechanical testing is crucial to understand the performance of these devices in pediatric epiphyseal bone. To our knowledge, there has not been a biomechanical analysis of ACL fixation devices in skeletally immature bone. Purpose: To compare cortically based button fixation with interference screw and sheath fixation in skeletally immature femoral epiphyseal cadaveric bone. Our hypothesis was that there would be no difference in peak load to failure, stiffness, or cyclic displacement between these 2 fixation constructs. Study Design: Controlled laboratory study. Methods: Fresh-frozen matched-pair knees from 3 pediatric cadaveric specimens were obtained. A synthetic graft was fixed in an all-epiphyseal femoral tunnel. Both the lateral and medial condyles were utilized to increase the sample size. Specimens were randomized and assigned to receive either an interference screw and sheath construct designed for pediatric patients or an adjustable loop cortical button. Biomechanical testing was performed to obtain ultimate load to failure, stiffness, total displacement after 500 cycles, and the failure mode for each condyle. Results: Each medial and lateral condyle in 3 pairs of skeletally immature cadaveric knees (ages 7, 9, and 11 years) was utilized for testing. One specimen was excluded after it failed by having a transphyseal fracture. The median peak load to failure was 769.80 N (interquartile range [IQR], 628.50-930.41 N) for the screw and sheath group and 862.80 N (IQR, 692.34-872.65 N) for the button group ( P = .893). The median displacement after 500 cycles for the screw and sheath group was 0.65 mm (IQR, 0.47-1.03 mm) and 1.13 mm (IQR, 0.96-1.25 mm) for the button group ( P = .08). The median stiffness of the screw and sheath group was significantly higher than that of the button group (31.47 N/mm [IQR, 26.40-43.00 N/mm] vs 25.22 N/mm [IQR, 21.18-27.07 N/mm], respectively) ( P = .043). Conclusion: When comparing femoral fixation with a screw and sheath construct developed for pediatric patients to an adjustable loop cortical button in skeletally immature bone, our results showed that fixation did not significantly differ with respect to cyclic displacement or peak load to failure. While the screw and sheath construct was significantly stiffer, its effect on clinical outcomes is not yet known. Clinical Relevance: With regard to femoral fixation, there is no significant biomechanical difference between the use of cortically based button fixation or interference screw and sheath fixation in pediatric epiphyseal cadaveric bone.

Purpose: To determine the volume of injury to the physis during anterior cruciate ligament (ACL) reconstruction in pediatric patients. Methods: Magnetic resonance imaging scans of 10 pediatric knees were converted into 3-dimensional models. Computer-aided design/computer-aided manufacturing software placed drill holes (6, 7, 8, and 9 mm in diameter) in these models, simulating tunnels used for ACL reconstruction. The software was used to calculate total physeal volume and volume of physis removed by the tunnel. The ratio of physeal volume removed to the total physeal volume was determined. Results: For 6-, 7-, 8-, and 9-mm-diameter drill holes, the mean percent of physeal volume removed/total physeal volume was 1.6%, 2.2%, 2.9%, and 3.8%, respectively, for the tibia and 2.4%, 3.2%, 4.2%, and 5.4%, respectively, for the femur. For all subjects, the volume removed was less than 7.0% for the tibia and 9.0% for the femur by use of drill holes from 6 to 9 mm. The tibial drill hole was centrally placed in all cases compared with a more peripheral drill hole placement of the femur. Conclusions: Drill hole placement during ACL reconstruction produces a zone of physeal injury. The overall volume of injury is relatively low, which reduces the risk of physeal arrest. With careful drill hole placement, the region of injury is central on the tibia, and the total volume of injury can be less than 5.0% of the physeal volume. For the femur, the total volume can be less than 5.0% as well. However, the region of injury is peripheral, which carries a higher risk of physeal arrest. Clinical Relevance: A better understanding of the relation between the ACL and physis may guide the placement of drill holes, which have a lower risk of producing physeal arrest.

BACKGROUND Widespread variation in state laws produces significant differences in state-to-state liability risk and insurance cost. These variations may produce higher medical liability for certain pediatric practitioners because many states have a significantly longer period of potential liability for physicians caring for children. This study reviewed state laws for variability in the period of medical liability for pediatric and adult patients and considered some of the impacts resulting from such variability. METHODS Statutes of limitations applicable to claims for medical malpractice were reviewed for all 50 states and the District of Columbia, as were laws that affect the statute of limitations based on a patient's age. For each state, the average, minimum, and maximum values for the statute of limitations in years were calculated for the following age groups: newborn, 6, 12, and 25 years. RESULTS In most states, the length of time a claimant has to bring a claim is longer for the youngest patients and decreases as patients get older. In the United States, the average time to bring a claim in years for a newborn and those aged 6, 12, and 25 years was 12, 8, 5, and 2 years, respectively. The maximum time to bring a claim in years for a newborn and those aged 6, 12, and 25 years was 23, 17, 11, and 5 years, respectively. CONCLUSIONS States demonstrate significant variability in the duration and application of statutes of limitations, with younger patients typically having a longer period to file a liability lawsuit. In most regions, pediatric practitioners face increased liability risk based upon significantly longer limitation periods for minor patients. Studies have suggested that medical students are considering specialty liability risk when choosing careers. Increased liability risk faced by pediatric specialists may lead to fewer practitioners entering these fields. Extended periods of liability for pediatric specialists need additional study to evaluate the effects on liability insurance, specialty choice, and specialty care access. LEVEL OF EVIDENCE Descriptive study (audit of existing laws), level of evidence 2.

The benefits provided by rapid prototyping (RP) of patient anomalies in complex surgeries of the pediatric spine and pelvis were elucidated and characterized.Surgeons involved in the study were solicited from the Texas Scottish Rite Hospital for Children and the network of Shriners Hospitals for Children throughout the United States. Rapid prototyping models were created at Boise State University through a federally funded Economic Development Agency grant (Economic Development Agency Project Number 07-79-05312). Rapid prototyping models and detailed survey forms were supplied to lead surgeons for 13 cases of multiplane spinal or pelvic deformity.Results indicated that surgeons found RP models useful for preoperative planning, reference during surgery, communication with patients, and for increasing the safety of the procedure. Rapid prototyping models also led to a reduction in operating time in 4 of the 5 surgeries to correct congenital scoliosis/kyphosis.Surgeons can expect properly constructed RP models to provide significant benefits for complex surgeries of the pediatric spine and pelvis in the areas of preoperative planning, intrasurgical navigation, and communication with patients. A reduction in operating time may also be expected for cases of congenital scoliosis/kyphosis.This study was a type II prospective observational study of physicians' perceptions of the use of RP models to assist with surgical cases. Results provided by this study suggest expected benefits from application of RP in surgeries of the pediatric spine and pelvis with complex deformities.

BACKGROUND While the characteristics of osteochondritis dissecans (OCD) of the knee that require surgery to heal have been described, several surgical techniques/procedures exist with no consensus established regarding timing of treatment and specific surgical intervention. In this study, we aim to determine current trends in surgical treatment for OCD lesions in the skeletally immature who have failed 6 months of nonoperative management by surveying a large cohort of orthopaedic surgeons. METHODS An electronic survey designed using REDCap to capture surgeon treatment preferences for OCD lesions was distributed to members of the Pediatric Orthopaedic Society of North America (POSNA). The survey inquired about treating physicians' training and demographics. It then offered a series of clinical vignettes alongside imaging describing patients with varying degrees of severity of OCD following nonoperative treatment. Surgeons were prompted to select from a variety of multiple-choice-based options for further patient management. Standard descriptive statistics were used to summarize and compare the responses. RESULTS Of the 129 POSNA members completing the pediatric survey, 97.7% were attending level orthopaedic surgeons, the majority identifying with an academic institution and treating mostly skeletally immature patients. In the skeletally immature population, the majority would treat intact, stable OCD lesions with drilling in a retroarticular or transarticular manner. Preferred treatment for unstable, salvageable lesions was screw fixation using bioabsorble materials or metal with variable pitch with no bone graft. The majority of respondents would treat unstable, unsalvageable OCD lesions with chondroplasty and osteochondral transplant/transfer or microfracture/drilling. CONCLUSIONS The POSNA membership appears to agree on principle in terms of treatment modalities for various stages of OCD lesions in the skeletally immature, whereas individual techniques of achieving these principles may vary. Members endorse drilling for stable intact lesions; fixation for unstable, salvageable lesions; and "defect fill" for unsalvageable lesions. CLINICAL SIGNIFICANCE OCD surgical treatment patterns can be used in future studies to determine which techniques are most effective for given indications, with the goal of designing a research-proven optimal treatment regimen for skeletally immature patients.

The AAOS Evidence-Based Guideline on Detection and Nonoperative Management of Pediatric Developmental Dysplasia of the Hip in Infants up to Six Months of Age includes both diagnosis and nonoperative management. This clinical practice guideline has been endorsed by the American Academy of Pediatrics (AAP), the Pediatric Orthopaedic Society of North America (POSNA), the Society for Pediatric Radiology (SPR), and the Society of Diagnostic Medical Sonography (SDMS). This brief summary of the AAOS Clinical Practice Guideline contains a list of the recommendations and the rating of strength based on the quality of the supporting evidence. Discussion of how each recommendation was …

Background: Understanding the pathogenesis of osteochondrosis/osteochondritis dissecans and other developmental orthopaedic diseases that are thought to occur secondary to defects in vascular supply to growth/epiphyseal cartilage has been hampered by the inability to image the vasculature in this tissue. This is particularly true in human beings due to limitations of current imaging techniques and the lack of availability of appropriate cadaveric samples for histological studies. Hypothesis: Susceptibility-weighted imaging, an MRI sequence, allows identification of characteristic differences in the vascular architecture in species that are affected by osteochondrosis/osteochondritis dissecans on the femoral condyle (humans and pigs) versus a species that is free of the disease (goat). Study Design: Controlled laboratory study. Materials: Distal femora from cadavers of juvenile humans (n = 5), pigs (n = 3), and goats (n = 3) were scanned in a 9.4-T MRI scanner using susceptibility-weighted imaging. Three-dimensional reconstructions were created, and minimum intensity projections were calculated in 3 planes to enhance visualization of the vascular architecture. Results: Susceptibility-weighted imaging allowed clear visualization of the epiphyseal vasculature in all species. Vascular architecture, with vessels primarily arising from the perichondrium, was similar in humans and pigs, which are predisposed to osteochondrosis/osteochondritis dissecans, and was starkly different from that present in goats, a species in which there are no reports of osteochondrosis/osteochondritis dissecans. Furthermore, vessels in the distal femoral predilection site disappeared with age in humans in a pattern similar to that reported previously in pigs. Conclusion: Nearly identical vascular architecture at the shared primary predilection site of osteochondrosis/osteochondritis dissecans in the femoral condyles in human beings and pigs suggests that vascular failure, which is known to be central to the pathogenesis of this disease in pigs, may also play a role in humans. Clinical Relevance: This assumption of a shared pathogenesis is supported by the pattern of disappearance of vessels with age at the primary predilection site of osteochondritis dissecans in humans, which is essentially identical to that which has been reported in pigs. Susceptibility-weighted imaging will likely help further elucidate this potential relationship in the future.

The AAOS Evidence-Based Guideline on Management of Hip Fractures in the Elderly includes both diagnosis and treatment. This clinical practice guideline has been endorsed by the Orthopaedic Trauma Association (OTA), the American Academy of Physical Medicine and Rehabilitation (AAPM&R), the American Society for Bone and Mineral Research (ASBMR), the United States Bone and Joint Initiative, the Hip Society, the American Association of Clinical Endocrinologists, the Orthopaedic Rehabilitation Association (ORA), and the American Geriatrics Society (AGS). This brief summary of the AAOS Clinical Practice Guideline contains a list of the recommendations and the rating of strength based on the quality of the supporting evidence. Discussion of how each recommendation was developed and the complete evidence report are contained in the full guideline at www.aaos.org/guidelines. ### ADVANCED IMAGING Moderate evidence supports MRI as the advanced imaging of choice for diagnosis of presumed hip fracture not apparent on initial radiographs. Strength of Recommendation: Moderate ★★★☆ ### PERIOPERATIVE REGIONAL ANALGESIA Strong evidence supports regional analgesia to improve preoperative pain control in patients with hip fracture. …

Surgical site infections (SSIs) make up about 23% of hospital-acquired infections and may cost up to 10 billion dollars annually in direct medical expenses. St. Luke's Health System of Boise, Idaho implemented a committee to reduce its incidence of SSIs, focusing on the orthopaedic and neurosurgical departments. After identifying risk factors associated with patient medical comorbidities, operating room practices, and type of procedure, Project Zero recommended changes. The implementation of a preoperative clinic and protocol management of environmental and procedural factors reduced the hospitals rate by 50%. Project Zero continues to research best practices for clean room management and preventative care, striving to reach the overall goal of zero infections.

This paper estimates the incremental hospital resource consumption associated with treating selected adverse events experienced by Medicare beneficiaries (MBs) undergoing total hip arthroplasty (THA). This retrospective study, using the Medicare Provider Analysis and Review file, identified 174,167 MBs who underwent THA in 2013. Overall, 20.16% of MB undergoing THA experienced at least one adverse event. MB experiencing any adverse event consumed significantly higher hospital cost ($3429) and had longer length of stays (1.0 day). The risk-adjusted incremental cost of treating adverse events ranged from a high of $27,116 (pneumonia) to a low of $2626 (hemorrhage or post-operative shock requiring transfusion). Most major adverse events occurred infrequently, however when adverse events occurred, they add substantially to the hospital resource costs of treating MB.